ABSTRACT Mexican Americans comprise the fastest growing segment of the older adult population in the U.S. They represent a group with distinct health and social characteristics that may influence their use of health care resources and health outcomes. We will study a national sample of Mexican American older adults participating in the Hispanic Established Populations for the Epidemiologic Study of the Elderly (EPESE) - a study supported by the NIA for 20 years. With the aging of the U.S. population and increase in persons over the age of 85, the number of frail individuals is projected to increase substantially in the coming decade. Frailty not only affects the older person?s function and quality of life, but is a burden for caregiving families and the U.S. healthcare system. Recent research indicates that frailty is a dynamic process and individuals may transition in-and-out of the stages of frailty. This research suggests that frailty is preventable and potentially reversible. The goal of the research is to better understand the long-term health outcomes, healthcare utilization, and life expectancy of this population with a focus on the impact of frailty and disability on Mexican American older adults. We will examine three aims. Aim 1. Explore transitions and trajectories in frailty stages (non-frail, pre-frail, and frail) over 20 years in Mexican American older adults. Aim 2. Develop life expectancy tables for older Mexican Americans based on stages of frailty. The tables will include frail-free life expectancy, disability life expectancy, frail life expectancy, and disability plus frail life expectancy. Tables will be developed for males and females. Aim 3. Examine the long-term health outcomes and healthcare utilization of Mexican American older adults. We will analyze how health outcomes (e.g., disability, cognitive function, and health related quality-of-life) are related to frailty status over time. The Hispanic EPESE data will be linked to Medicare files to examine the utilization of health and medical services including, emergency room visits, hospitalizations, post-acute care services (e.g., skilled nursing), and health care costs over time. The sample includes 2,438 participants from the Hispanic. A standard measure of physical frailty has been collected eight times over a period of 20 years along with measures of disability and cognitive function. We will link the Hispanic EPESE data with Medicare claims files to obtain information on the use of health resources, presence of chronic diseases, hospitalization, and the use of skilled nursing and other post-acute services. We will use a growth curve model with ordinal measures and generalized linear mixed models to examine longitudinal changes in frailty. The transitions across frailty stages (non-frail, pre-frail and frail) will be compared for men and women with a focus on persons who have remained non-frail, or have transitioned from a state of frailty back to physical and/or functional independence.